Jack column construction



March 13, 1951 G DEAN 2,544,780

JACK COLUMN CONSTRUCTION Filed June 16, 1949 2 Sheets-Sheet 1 March 13, 1951 'G. H. DEAN 2,544,780

JACK COLUMN CONSTRUCTION Filed June 16, 1949 2 Sheets-Sheet 2 INVENTOR.

air-m Patented Mar. 13, 1951 UNITED PATENT OFFICE.

asunso 7740K Comm C TRUCTION G or e. H:..D.ean, Nom o g App icati n are 16. 1949. Serial No. 9 7 o clause: (01. assess),

The present invention relates to support columns, and has particular reference to'a novel construction for a jack column The principal object of they invention is to provide a jack column which has interlocking parts. whereby the column cannot collapseupon failure of the jack screw or upon disengagement of the jack screw at maximum lift.

Another object of the invention is to provide a jack column with a'screw shield, forpreventing damage to the screwthreads.

A further object is to provide a jack column with a support top which relieves the screw against excessive pressures resulting from tinavoidable tilting of the upper contact plate.

An additional object of the invention is to improve the screw housing" and its permanent mounting in the support column.

With the above and other objects and advantageous features in view, the invention includes a no-vel'arrangement ofparts more fully disclosed in the detailed description following. in conjunction with the accompanying drawings. and more specifically defined in the claims appended thereto.

In the drawings,

Fi 1.. is afront, elevation oi a oolumnia kembodying the invention, parts beingbrolssn aways:

Fig. 2 is a vertical section on. the, line 2-2 of Fig. 1, jack being in low position;

Fig. 3 is a sectional detail showing the upper jack parts when in. extreme raised position;

Fig. 4 is a plan view of the upper contact plate;

Fig. 5 is an enlarged sectional detail of the upper part of the jack column;

Fig. 6 is a section showing the jack screw housing and the upper cylinder parts;

Fig. 7 is a bottom plan view of the housing;

Fig. 8 is a top plan view of the jack screw and its shield; and

Fig. 9 is a sectional detail of a modified mountin arrangement for the jack screw and its shield.

It has been found desirable to provide an improved jack column which is safe, which cannot collapse, and which remains permanently rigid under compression stresses even when the pressure conditions are slightly oil-vertical. To. this end, I have rigidly looked a jack screw housing into a support column, preferably with solidified concrete, and I have equipped the jack screw with a lower extension and with a shield which telescopes with respect to the jack screw housing and the upper end of the support column so that failure of the jack screw or separation threading of the jack screw out of the housing cannot release the jack screw: from the column. I' havefu-rther provided the jack screw with an auxiliary top which engages the upper contact plate whenever it is subject to unavoidable tilt ing, the. parts being so arranged that excessive bending stress on the jack screw is distributed and relieved.

Referring to.- the. drawings, the novel jack column NJ includes the usual base plate l-I sups port column I2, and upper contact plate I 3, which is adapted to be raised by: means ofa jack screw [4, as hereinafter described.

The base plate II is preferably circular. and has an annular upwardly extending flange or rim 5 in which the. lower end IB' of the column f2: seats. The column I2 is tubular,- oft prefer-i ably cylindrical form, and has a jack screw house ing- IT'moun-ted in its upper end, the, housing i 'l: being hollow, with an annular flange l8. which has a plurality of spaced depending bosses.- I9,

see Figs. 6. and '7', preferably four in number. Each boss la -has a peripheral recess 28, and suitable corresponding openings 2| are provided. in the column wall, whereby welding material 22- may be applied to permanently lockthe housing to. the column.

As clearly shown-in Fig. 2, the housinghas a lower extension 23', which may have an opening 24 closed by a threaded closure plug 25., whereby the column lt2'may be filled with concrete 28,.with'out entry or seepage of concrete into the housing. The spaced bosses lock; to, the concrete and provide a firm grip between the housing and the concrete. The upper end 2'! of the housing preferably slightly tapers and has a thickened top 28 which is bored and threaded as indicated at 29 to provide a rigid support for the threads of the jack screw I4.

The jack screw has a depending reduced extension 30 at its lower end, and a reduced upper portion 3| which is stepped down to provide a bearing shoulder 32 and a centering plug 33 adapted to seat in the central opening 34 of the upper contact plate l3. The upper plate I3, see Figs. 4 and 5, is generally square, with bolt or screw holes 35 for attachment to the under surface of a floor beam or the like, and has an annular bearing collar 36 for engaging the jack screw shoulder 32, a secondary bearing shoulder 31 spaced from the shoulder 32 and connected thereto by radial ribs 38, and an annular de-- pending ridge 39. p

The jack screw is provided with a shield 40, see Figs. 2 and 3, in the form of a cup with a wall 4| of tapered section depending from a support plate ridge 39 and are adapted to engage the secondary bearing shoulder 31 if the upper contact plate I3 is tilted, to thus distribute and relieve the compression strain on the jack screw shoulder 32. The support plate 42 has a transverse bore 45 to receive the end of a turning pipe or rod, for turning the jack screw, and has a preferably hexagonal periphery to permit turning by means of a wrench if desired.

Should the jack screw break for any reason,

the telescoping relation of the upper column end 44, the shield 40 and the housing 21 prevent collapse of the jack column. Also, if the jack screw is turned to screw out of the housing, see Fig. 3, it cannot leave the housing, as the lower end 30 merel rotates, whereby collapse is prevented. The shield 40 effectively prevents access to the jack screw and damage to the threads.

If desired, the locking between the shield support plate 42 and the upper jack screw portion 3! may be increased by recessing the portion 31 as indicated at 46 as well as the plate 42 to receive welding metal, as illustrated in Fig. 9, the number of recesses being also increased.

Although I have described a specific constructional embodiment of the invention, it is obvious that changes in the size, shape and arrangement of the parts may be made to suit different requirements for column jacks, without departing from the spirit and the scope of the invention as defined in the appended claims.

I claim:

1. In a jack column, a support column, a jack screw housing secured within the upperv end thereof, a jack screw threaded in said housing, a contact plate mounted on the upper end of .the

jack screw, and a shield element secured tothe upper end of the jack screw and having ade pending wall positioned in intermediate telescoping relation to the column upper end and the jack screw housing.

2. In a jack column, a support column, a jack screw housing secured within the upper end thereof, a jack screw threaded in said housing,

4 a contact plate mounted on the upper end of the jack screw, and a shield element secured to the upper end of the jack screw and having a depending wall positioned in intermediate telescoping relation to the column upper end and the jack screw housing, said jack screw having a reduced extension at the lower end thereof.

3. In a jack column, a support column, a jack screw housing secured within the upper end thereof, a jack screw threaded in said housing, a contact plate mounted on the upper end of the jack screw, and a shield element secured to the upper end of the jack screw and having a depending wall positioned in intermediate telescoping relation to the column upper end and the jack screw housing, said contact plate having an annular depending ridge.

4. In a jack column, a support column, a jack screw housing secured within the upper end thereof, a jack screw threaded in said housing, a contact plate mounted on the upper end of the jack screw, and a shield element secured to the upper end of the jack screw and having a depending wall positioned in intermediate telescoping relation to the column upper end and the jack screw housing, said contact plate having an annular depending ridge, and a supplemental annular bearing shoulder, and said shield element having an upper plate adapted to seat within the contact plate ridge.

5. A jack screw housing for a jack column, having an elongated hollow body, anannular flange adjacent the lower end thereof, and spaced bosses depending from said flange, the upper end of the housing being threaded to receive a jack screw.

6. A jack screw housing for a jack column, having an elongated hollow body, an annular flange adjacent the lower end thereof, and spaced bosses depending from said flange, the upper end of the housing being threaded to receive a jack screw, the bosses having recesses adapted to receive welding metal.

GEORGE H. DEAN.

REFERENCES CITED UNITED STATES PATENT Name Date Slonecker J an; 1:, .1924

Number 

